1. Field of the Invention
The invention relates generally to the fields of data processing, recording and transmission, and more particularly to data multiplexing and demultiplexing techniques.
2. Brief Description of the Prior Art
In the area of recording data on physical media, such as on magnetic disks and tapes, or by means of electronic beams, there exists a need to space adjacent tracks of data closely together. Many elaborate techniques have been developed to achieve these ends, but these all have had the characteristic of recording and reading one track of data at a time. However, it is often difficult to maintain the narrow track spacing necessary for single track reading. In electron beam recording, for example, written data tracks "spread" on recording, thereby making it difficult to maintain well-defined single tracks.
Similarly, in the field of data transmission, there exists the need to transmit multiple data streams over a single channel. This need has been addressed in the past using time division techniques, such as multiplex telegraphy, as well as frequency multiplexing schemes, such as frequency interleaving methods used in color television. However, none of these approaches is satisfactory to high speed digital data transmission.
The present invention, therefore, primarily concerns the demultiplexing of several data streams simultaneously. In the data recording art, the invention is particularly useful for reading several data tracks simultaneously, thereby reducing the need for maintaining track spacing. In the data transmission art, the invention is useful for demultiplexing a composite signal, consisting of two or more data streams.